This application claims priority of Taiwan Patent Application Serial No. 090119017 filed on Aug. 3, 2001.
Various aspects of the present invention relate to data input devices for a portable digital processing device. More particularly, various aspects relate to a data input device especially adapted for a personal digital assistant (PDA).
Since the birth of notebook computers, many types of small-sized computers have been produced. A common problem associated with the smaller size, however, is that miniaturized input/output devices (such as keyboards) can be cumbersome, slow and uncomfortable to use.
The personal digital assist (PDA), which is typically smaller than a notebook computer, has become very popular in recent years. PDAs typically include a liquid crystal display (LCD) for receiving input and displaying information to the user. Unlike the conventional desktop computer, a PDA does not typically have a conventional keyboard, and has only limited control buttons thereon and a stylus that can be used to input data on the display. The PDA may store handwriting in bitmap or another graphical form, but this technique is typically cumbersome to process, requires a large amount of memory and lowers the efficiency of the PDA. Another method for inputting data to a PDA involves handwriting recognition software installed in the PDA. The PDA encoder translates handwriting to ASCII or another alphanumeric code, and then stores the alphanumeric data. Alternatively, the PDA may have a virtual keyboard. When the virtual keyboard is displayed on the screen, a user can utilize the stylus or control buttons to activate keys within the virtual keyboard to input data.
Conventional input methods for PDAs, however, are not typically as efficient as using a conventional computer keyboard. A typical PDA does not include a conventional keyboard because of relatively large size of the keyboard. Various forms of externally-connectable keyboards have been fashioned to work with PDAs, however. When a user wants to input data, the user connects the separable keyboard to the PDA for rapid data entry.
There are at least two types of the conventional separable keyboards for PDAs. One type is similar to the conventional computer keyboard, but smaller in size. The other is a foldable keyboard whereby a keyboard is separated into at least two parts that are foldably connected to each other. When the foldable keyboard is not in use, it can be folded and conveniently stored.
A common problem with prior art folding keyboards is that key switches in the keyboard foldable keyboards can become deformed when the keyboard is folded. Although the overall height of keyboard is reduced when the keyboard is folded, internal elastic elements (i.e., rubber domes or, springs) used to hold or bias the keyboard in position may deteriorate while the keyboard is folded. One way to solve the problem is to provide higher sidewalls along the rim of the foldable keyboard. The higher side-walls, however, typically block the users"" hands when he or she operates the key switches, making the keyboard difficult to operate because the user typically has to lift his/her palms to avoid the sidewalls.
One aspect of the present invention provides a foldable input device with keys that are not necessarily compressed when the input device is folded up. When a user operates the input device in the extension state, the user is allowed to depress the keys near of the side-wall closest to the user without lifting his/her palms away from the table.
Various embodiments of the present invention include a shell that includes a first base having an edge, and a sideboard connected pivotally to the edge. The sideboard has two states. When the sideboard operates in the first state, it is substantially perpendicular to the first base. When the sideboard operates in the second state, it is parallel to the first base substantially. Various embodiments have at least one rotatable sideboard at the side close to the user.